In a much anticipated announcement, former U.S. Vice President Joe Biden, who served two terms under Barack Obama, has announced he will contest the U.S. presidency in 2020.

Biden, 76, will join a packed field of candidates bidding for the Democratic Party nomination.

His announcement, which came as no surprise, was via a campaign video released on Thursday morning.

In the video, the former VP took aim at current President Donald Trump's response to the white supremacist rally in Charlottesville, Virginia, in August 2017.

"He said there were quote some very fine people on both sides," Biden said. "With those words, the president of the United States assigned a moral equivalence between those spreading hate and those with the courage to stand against it. And in that moment, I knew the threat to this nation was unlike any I had ever seen in my lifetime."

Biden said the 2020 race would be a "battle for the soul of this nation."

"The core values of this nation, our standing in the world, our very democracy, everything that has made America, America, is at stake," he said. "That's why today I'm announcing my candidacy for President of the United States."

Later a statement from Biden's office said he would "lay out his vision for unifying America with respected leadership on the world stage," at a rally in Philadelphia next month.